PG16 compatibility - Part 3
Check out part 1 42d956888d
and part 2 0d503dd5ac
This commit is in the series of PG compatibility. It makes some changes
to our tests in order to be compatible with the following in PG16:
Use debug_parallel_query in PG16+, force_parallel_mode otherwise
Relevant PG commit
5352ca22e0
5352ca22e0012d48055453ca9992a9515d811291
HINT changed to DETAIL in PG16
Relevant PG commit:
56d0ed3b75
56d0ed3b756b2e3799a7bbc0ac89bc7657ca2c33
Fix removed read-only server setting lc_collate
Relevant PG commit:
b0f6c43716
b0f6c437160db640d4ea3e49398ebc3ba39d1982
Fix unsupported join alias expression in sqlancer_failures
Relevant PG commit:
2489d76c49
2489d76c4906f4461a364ca8ad7e0751ead8aa0d
More PG16 compatibility commits are coming soon ...
Similar to https://github.com/citusdata/citus/pull/7077.
As PG 16+ has changed the join restriction information for certain outer
joins, MERGE is also impacted given that is is also underlying an outer
join.
See #7077 for the details.
PG16 compatibility - Part 2
Part 1 provided successful compilation against pg16beta2.
42d956888d
This PR provides ruleutils changes with pg16beta2 and successful CREATE EXTENSION command.
Note that more changes are needed in order to have successful regression tests.
More commits are coming soon ...
For any_value changes, I referred to this commit
8ef94dc1f5
where we did something similar for PG14 support.
Prior to this commit, the code would skip processing the
errors happened for local commands.
Prior to https://github.com/citusdata/citus/pull/5379, it might
make sense to allow the execution continue. But, as of today,
if a modification fails on any placement, we can safely fail
the execution.
The first commit show the problem in action. The second commit
includes the fix and the test fixes.
Tradionally our planner works in the following order:
router - > pushdown -> repartition -> pull to coordinator
However, for INSERT .. SELECT commands, we did not support "router".
In practice, that is not a big issue, because pushdown planning can
handle router case as well.
However, with PG 16, certain outer joins are converted to JOIN without
any conditions (e.g., JOIN .. ON (true)) and the filters are pushed down
to the tables.
When the filters are pushed down to the tables, router planner can
detect. However, pushdown planner relies on JOIN conditions.
An example query:
```
INSERT INTO agg_events (user_id)
SELECT raw_events_first.user_id
FROM raw_events_first LEFT JOIN raw_events_second
ON raw_events_first.user_id = raw_events_second.user_id
WHERE raw_events_first.user_id = 10;
```
As a side effect of this change, now we can also relax certain
limitation that "pushdown" planner emposes, but not "router". So, with
this PR, we also allow those.
Closes https://github.com/citusdata/citus/pull/6772
DESCRIPTION: Prevents unnecessarily pulling the data into coordinator
for some INSERT .. SELECT queries that target a single-shard group
and the expression originating from the source. If the types are different, Citus uses
different hash functions for the two column types, which might lead to incorrect repartitioning
of the result data
Previously, we only checked whether the relations are colocated, but we
ignore the shard indexes. That causes certain queries still to be
accidentally router. We should enforce colocation checks for both shard
index and table colocation id to make the check restrictive enough.
For example, the following query should not be router, and after this
patch, it won't:
```SQL
SELECT
user_id
FROM
((SELECT user_id FROM raw_events_first WHERE user_id = 15) EXCEPT
(SELECT user_id FROM raw_events_second where user_id = 17)) as foo;
```
DESCRIPTION: Enforce shard level colocation with
citus.enable_non_colocated_router_query_pushdown